The goal of this project is to examine pharmacokinetic functions of the lung with regard to both endogenous and exogenous chemicals. The pharmacokinetics of these chemicals will be related to environmentally induced pulmonary damage. An isolated perfused lung is used which permits examination of the pharmacokinetics of chemicals reaching the lungs both from the circulatory system and from the inhaled air. BIBLIOGRAPHIC REFERENCES: Wilson, A.G.E., Law, F.C.P., Eling, T. E., and Anderson, M. W.: Uptake, metabolism, and efflux of methadone in "single pass" isolated perfused rabbit lungs. J. Pharmacol. Exp. Ther. 199: 360-367, 1976. BIBLIOGRAPHIC REFERENCE: Wilson, A.G.E., Law, F.C.P., Eling, T.E., and Anderson, M.W.: Uptake, metabolism, and efflux of methadone in "single pass" isolated perfused rabbit lungs. J. Pharmacol. Exp. Ther. 199: 360-367, 1976.